watanabe_1952 ============= K\. Watanabe, E\. C\. Y\. Inn and M\. Zelikoff, "Absorption coefficients of gases in the vacuum ultraviolet", J\. Chem\. Phys\. 20, 1969 \(1952\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1063/1\.1700353 `__ **Source kind:** measurement **Recorded technique:** Photoelectric absorption \(letter\)\: a Baird 1 m vacuum monochromator \(exit slit 0\.05 mm, band width 0\.85 A\), an H2 discharge source, an absorption cell with LiF windows between the exit slit and a sodium\-salicylate\-coated 1P21 photomultiplier; repeated measurements with the cell empty and filled against the source drifts \(\+\-5 percent\); 1050\-2500 A \(p\. 1969\)\. **Materials in structured entries:** CO2, O2 **Dataset quantities:** absorption\_cross\_section **Contents:** 4 datasets; 0 formulas. Curation notes -------------- Journal pages 1969\-1970 = PDF pages 2\-3 \(page 1 is the publisher's cover; the letter starts at the foot of the first column of p\. 1969, after the end of another letter\)\. Identity checked against the page image \(pdf 2\)\: Watanabe, Inn and Zelikoff, 'Absorption Coefficients of Gases in the Vacuum Ultraviolet', J\. Chem\. Phys\. 20, 1969 \(1952\), received 13 October 1952, a letter to the editor with no part number\. It is the preliminary communication of the series, not its Part I\: Part III \(inn\_1953\) refers to 'Part I of this series' for the method, which is the O2 paper \(watanabe\_1953, J\. Chem\. Phys\. 21, 1026 \(1953\)\); Part II is zelikoff\_1953 \(N2O\)\. The library's OCR of this page is poor \('10SQ\-2S00A', '14S0A'\); the values below were read from the page images\. Gases\: O2 \(Fig\. 1, 1200\-1550 A, log scale, with Ladenburg and Van Voorhis's curve L\-V\) and CO2 \(text only\); 'several gases' are announced for a fuller report\. Quantity\: k in cm^\-1 'base e'; the reference state is not stated in the letter\: NTP \(0 C, 1 atm\) as in the full papers of the series \(watanabe\_1953, zelikoff\_1953, inn\_1953\) is assumed, and the datasets store k with scale = 1e18 / n0, n0 = 2\.6867801e19 cm^\-3 \(ideal gas\), to Mb, as watanabe\_1953 and inn\_1953\. Temperature not stated\. No accuracy statement beyond the source drifts \(\+\-5 percent\)\. O2 text \(p\. 1969\)\: the Schumann\-Runge continuum maximum 380 cm^\-1 at 1420 A, 'in contrast to the accepted value of about 490 cm^\-1 at 1450A obtained by Ladenburg and van Voorhis' \(ladenburg\_1933\), and a more asymmetric distribution; narrow continua or diffuse bands D, E, F at about 1352, 1330 and 1293 A \(reported by Tanaka\) and very diffuse bands A, B, C below 1270 A \(positions only, figure\)\. These are the same measurements that watanabe\_1953 reports in full \(380 cm^\-1 at about 1420 A there too\)\: the O2 datasets here are checks, not independent\. At Lyman alpha 0\.33 cm^\-1, 'in good agreement with the value 0\.315 cm^\-1 found by Preston for a corresponding pressure \(7\.5 cm Hg\)' \(pressure\-dependent; watanabe\_1953 extrapolates 0\.27 cm^\-1 to zero pressure\)\. Ditchburn and Heddle \(ditchburn\_1953, p\. 69\) quote this letter's maximum as '380 cm^\-1 at 71000 cm^\-1' and suspect scattered light\. CO2 text \(pp\. 1969\-1970\)\: 2\.0 cm^\-1 at Lyman alpha \(Preston 2\.01, reproduced, not extracted\); the continuum 'as much as a factor two greater' than Wilkinson and Johnston's in 1450\-1700 A, nearly forty diffuse bands on a continuum extending to about 1200 A \(Wilkinson and Johnston's bands at 1662, 1673, 1690 A\), and 'at least two maxima of about 14 cm^\-1 and 18\.5 cm^\-1 at 1475A and 1335A'\. The full CO2 paper \(inn\_1953\) gives 1\.97 cm^\-1 at Lyman alpha and the continua maxima at about 1475, 1332 and 1121 A but their k only in figures\: the two maxima here are the only printed values\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- watanabe\_1952/o2\_sr\_maximum ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "o2_sr_maximum", "material": "O2", "table": "text", "quantity": "absorption_cross_section", "unit": "Mb", "scale": 0.03721927208, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "use": "check" } 1 inline points in the source record. p\. 1969\: 'the maximum coefficient of the Schumann\-Runge continuum of O2 was found to be 380 cm^\-1 \(base e\) at 1420A'\. scale = 1e18 / n0 \(NTP assumed\) to Mb\. The preliminary report of the measurement published in full as watanabe\_1953 \(sr\_maximum, the same 380 cm^\-1\)\: a check, not fitted beside it\. Uncertainty not stated\. watanabe\_1952/o2\_lyman\_alpha ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "o2_lyman_alpha", "material": "O2", "table": "text", "quantity": "absorption_cross_section", "unit": "Mb", "scale": 0.03721927208, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "use": "excluded" } 1 inline points in the source record. p\. 1969\: 'At Lyman alpha, the absorption coefficient was 0\.33 cm^\-1', compared with Preston's 0\.315 cm^\-1 'for a corresponding pressure \(7\.5 cm Hg\)'\. Excluded\: a pressure\-dependent value at about 75 mm Hg in a window between bands; watanabe\_1953 gives 0\.30 at 70 mm and the zero\-pressure 0\.27 cm^\-1 \(its lyman\_alpha dataset\)\. The letter names the line only; 1215\.7 A as in watanabe\_1953 \(from metzger\_1964 Table 1\)\. watanabe\_1952/co2\_lyman\_alpha ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "co2_lyman_alpha", "material": "CO2", "table": "text", "quantity": "absorption_cross_section", "unit": "Mb", "scale": 0.03721927208, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "use": "check" } 1 inline points in the source record. p\. 1969\: 'Our result \(2\.0 cm^\-1\) for CO2 at Lyman alpha also agrees with his carefully determined value \(2\.01 cm^\-1\)' \(Preston's\)\. scale = 1e18 / n0 \(NTP assumed\) to Mb\. The full paper inn\_1953 gives 1\.97 cm^\-1 at 1216 A \(its lyman\_alpha, primary\)\: this preliminary value is a check\. The letter names the line only; 1215\.7 A as in watanabe\_1953\. watanabe\_1952/co2\_continuum\_maxima ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "co2_continuum_maxima", "material": "CO2", "table": "text", "quantity": "absorption_cross_section", "unit": "Mb", "scale": 0.03721927208, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "use": "primary" } 2 inline points in the source record. p\. 1970\: 'The continuum itself has at least two maxima of about 14 cm^\-1 and 18\.5 cm^\-1 at 1475A and 1335A, respectively' \(the continuum under the diffuse bands\)\. scale = 1e18 / n0 \(NTP assumed\) to Mb\. Approximate \('about'\); uncertainty not stated\. The same group's full CO2 paper \(inn\_1953\) places the maxima at about 1475 and 1332 A but gives k only in figures, so these are the only printed values\: primary, preliminary \(to confirm against inn\_1953's Fig\. 1\)\. Formulas -------- No formulas are recorded. Corrections ----------- No dataset errata are recorded in this source record. Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register ` for the checks and decisions.